1. Field of the Invention
The present invention relates to a vibration-proof construction method, more particularly to a vibration-proof construction method for preventing or reducing the vibrations from vibration generating sources such as a road, railroad structure, or the like, to surrounding structures and the ground surface, by suppressing vibration propagation directly underneath the vibration generating sources or in the nearby ground.
2. Description of the Related Art
In recent years, vibrational disturbances along side of roads, railroad structures, and the like have frequently occurred due to traffic vibration or mechanical vibration. In particular, the negative effects due to such vibrations affecting surrounding houses and residents are serious with heavy traffic or close by railway tracks, and accordingly effective and efficient countermeasures for suppressing such vibrations have been strongly demanded.
As conventionally known suppression methods, for example, there is a vibration-screening trench construction method by providing a hollow space on a propagation path of vibrations in the ground, a vibration-impeding underground wall construction method by filling in the hollow trench with a suitable material, and so forth. These construction methods are methods to obtain vibration-proofing effects by directly blockading vibrations which propagate in the ground by the hollow trench or by the underground wall, but the former method has difficulties not only in increased costs in order to perform additional construction for building soil-retaining structures or supporting members, because it is realistically impossible to retain the hollow trench as it is, but also in losing vibration-blocking effects due to the additional construction. On the other hand, the latter method does nothing but replace the hollow trench with the underground wall having a constant quality of material so as to eliminate the need to perform the additional construction in the former method, so that the latter method cannot obtain sufficient vibration-proof effects as compared with the former method.
As a solution of these problems, the present inventors have proposed an anti-vibration method (the Wave Impeding Block (WIB) construction method using horizontal blocks) for solving the problems by laying flat blocks in the underground (Japanese Patent No. 2850187 (claims, etc.)), and furthermore in a later application have proposed an improved construction method (Japanese Patent No. 2764696 U.S. Pat. No. 5,779,397 (Claims, tc.)). These techniques involve flat blocks with a predetermined size, stiffness, and depth, are laid underground beneath or around a substructure which generates vibration or receives vibration. This has been realized based upon a theory regarding wave propagation in the ground (identification method for propagation/non-propagation phenomenon of waves) which had been established by the present inventors.
Moreover, with the above-described WIB method, a problem has remained in that anti-vibration effects are low as to vibrations with a low-frequency band of below 5 Hz, and also as to earthquakes, artificial vibration sources such as traffic vibration, and so forth, in ground influenced by low-frequency bands. In order to solve this problem, the present inventors have proposed a technique to obtain anti-vibration effects as to the vibration with a low-frequency band of below 5 Hz while taking advantage of the WIB construction method (see Japanese Unexamined Patent Application Publication No. 2000-282501 (claims, etc.)).
Furthermore, the present inventors made studies to realize improvement of vibration-proof effects based upon the theory regarding wave propagation within the ground described in the foregoing Japanese Patent No. 2850187, and as a result of these studies, have found that employing a building structure which takes advantage of the physical properties of scrap tires can obtain excellent vibration-proof effects which cannot be obtained in the conventional methods, and have presented their discovery to the Society (The 36th Geotechnical Conference Presentation (2001 Presentation Lectures, May 8, 2000, Japanese Geotechnical Society))
Although any of the above-described vibration-proof construction methods proposed by the present inventors is an effective vibration suppressing method, in recent years, the required properties are being increased more and more, furthermore, suppressing construction costs including material costs has been strongly demanded more than ever.